Polystyrene-Encapsulated Carbonyl Iron Microcapsules: A Corrosion-Resistant Microwave Absorber

Carbonyl iron powder is a widely used microwave-absorbing material due to its numerous advantages. However, carbonyl iron powder is prone to corrosion in high-salt-spray environments, reducing the service life of the composite material and limiting its applications, particularly in marine environments. In this study, we prepared polystyrene-encapsulated carbonyl iron microcapsules via in-situ polymerization and investigated their structure and properties. The results show that the coating of the polystyrene shell did not affect the crystal structure of the carbonyl iron and hardly weakened its electromagnetic properties. Compared to uncoated carbonyl iron powder, polystyrene-encapsulated carbonyl iron microcapsules exhibited superior corrosion resistance in both HCl solution and salt-spray environment. This work offers a potential solution for enhancing the durability of microwave-absorbing material in corrosive environments. With this simple, effective, and low-budget procedure, the cost of microwave-absorbing coating used in marine environments would be significantly reduced.